Process for preparing dyeings and prints fast to light on synthetic fibers

ABSTRACT

Process for preparing dyeings and prints which are fast to light and not capable of being affected by dyeing accelerators (carriers), on synthetic fibrous material, preferably linear polyester fibers, with insoluble dyestuffs, by subjecting the dyeings and prints prepared in the usual manner on textile articles with aqueous preparations of said dyestuffs with the aid of carriers to an aftertreatment in an organic solvent or solvent mixture.

United States Patent 1 Birke et al.

[451 July 15,1975

1 1 PROCESS FOR PREPARING DYEINGS AND PRINTS FAST TO LIGHT ON SYNTHETIC FIBERS [75] Inventors: Walter Birke; Hans-Ulrich von der Eltz, both of Frankfurt am Main; Wolfgang Kunze, Hofheim, Taunus; Franz Schiin, Frankfurt am Main, all of Germany [73] Assignee: Hoechst Aktiengesellschaft,

Frankfurt am Main, Germany [22] Filed: Mar. 5, 1973 [21] Appl. No.: 338,026

[30] Foreign Application Priority Data Mar. 10, 1972 Germany 2211679 [52] US. Cl. 8/173; 8/174; 8/175; 8/74 [51] Int. Cl D06p 5/04 [58] Field of Search 8/173, 174, 175, 74

[56] References Cited UNITED STATES PATENTS 3,667,898 6/1972 Bergman et a1 8/94 3,706,525 12/1972 Blackwell et a1. 3,764,262 10/1973 Hildebrand et a1. 8/94 Primary ExaminerLeland A. Sebastian Assistant ExaminerB. l-lunt Attorney, Agent, or FirmCurtis, Morris & Safford [57] ABSTRACT 5 Claims, N0 Drawings PROCESS FOR PREPARING DYEINGS AND PRINTS FAST TO LIGHT ON SYNTHETIC FIBERS The present invention concerns a process for preparing dyeings and prints fast to light on synthetic fibrous material.

For the dyeing of polyester fibres with disperse dyestuffs, there are practically the following three principal possibilities:

a. dyeing in an aqueous medium according to the exhaustion method at boiling temperature with the addition of a carrier, the auxiliary agent acting as fiber-opener;

b. dyeing according to the exhausting method under high temperature dyeing conditions in the absence of a carrier;

c. dyeing according to the pad-heat-fixation process.

In connection with these variants for preparing dyeings on polyester material, it is known to all skilled in the art that in many cases of dyeing with the addition of a carrier there is a deterioration of the fastness to light of the dyeings. In this respect the reaction of the various carrier substances is quite different. The carrier systems generally applied at present contain as active carrier components the following chemical compounds:

1. aromatic carboxylic acid esters 2. chlorinated aromatic hydrocarbons 3. phenol derivatives and diphenyl, and

4. naphthalene derivatives The carrier substances of groups (1) and (2), for example benzoic acid methyl ester, salicy-lic acid methyl ester, mono-, diand trichlorobenzenes or -toluenes and similar compounds do not affect the fastness to light of the dyeings or may be removed from the fiber by a simple treatment, for example, by drying in the air or at temperatures which are usual in the industry, or lower.

The carriers of groups (3) and (4) are mainly composed on the basis of o-phenylphenol or its alkali metal salts, diphenyl and methylnaphthalenes. With regard to diminishing the fastness to light the diphenyl shows the best reaction. By a light heat treatment, for example at drying temperatures which are usual in the industry, the diphenyl remaining in the fiber during the dyeing process can be eliminated to such an extent that a yellowing and thus a deterioration of the fastness to light does no longer occur. With the other representatives of the compounds listed above the results arequite different; o-phenylphenol and particularly methylnaphthalenes can only be removed from the fiber by a special aftertreatment with heat, a treatment which has absolutely nothing to do with the term drying. In the case of methylnaphthalenes which in this regard show the most unfavourable results, a temperature of at least 140C is necessary at which the dried goods have to be treated for at least 3 minutes in order to remove the carrier remainders to such an extent that a deterioration of the fastness to light of the dyed goods can no longer be observed. The expert learns from this fact that carriers on the basis of the last-mentioned compounds which are widely used in the industry have their limits and cannot be used where no special aftertreatment with heat can be carried out, for example where there are no suitable apparatuses, for example for drying muffs, or where the properties of the fibers can be impaired, e.g. in the case of texturized fibers.

Now we found that dyeings and prints which are fast to light and not capable of being affected by dyeing accelerators (carriers) can be prepared with insoluble dyestuffs on synthetic fiber material, preferably linear polyester fibers, by subjecting the dyeings and prints prepared in the usual manner on textile articles with aqueous dyestuff preparations with the aid of carriers to an aftertreatment in an organic solvent or solvent mixture.

As organic solvents for the aftertreating baths there may be used according to the present process halogenated especially aliphatic hydrocarbons, alcohols, ethers, esters, etc. preferably organic solvents known from the dry-cleaning, for example perchloroethylene, trichloroethylene, l,l l-trichloroethylene, gazolines, l,2,2-trifluorotrichloroethane, methylene chloride and also lower aliphatic alcohols having one to three carbon atoms.

The dyed textile materials can be aftertreated subsequently at a temperature between the freezing point and the boiling point of the organic solvent used, preferably and practically at a temperature between 20C and 80C.

The time of treatment depends on the temperature of the aftertreating bath and is generally between 5 and 15 minutes.

In order to achieve optimum results, it is convenient to determine the best possible treating temperature by a short preliminary test, for example by treating for about 10 minutes at various temperatures a strip of the dyed polyester material with the solvent or solvent mixture selected, the temperature intervals being from 5 to 5 degrees. Depending on the dyestuff used and the intensity of the dyeing, this preliminary test will result in a coloration of the solvent dyebath which is increasing with the rise of the temperature.

In order to obtain optimum results at the aftertreatment with regard to the removal of the carrier remainders from the fiber, a high temperature is selected for the aftertreating bath which is sufficiently high to be accepted according to the results of the preliminary test without too strong a staining of the aftertreating bath or an obvious brightening of the aftertreated dyeing occuring.

As already mentioned, different dyestuffs and different depths of color act in a different manner in this respect. The various organic solvents too show a somewhat different action in this regard.

In many tests with various dyestuffs and dyestuff combinations the following temperature ranges were determined as the most efficient ones for the appropriate solvents and solvent mixtures listed:

trichloroethylene 30 to 50C perchloroethylene 60 to C methanol 40 to 60C mixture of 50% by volume of methylenechloride and 50% by volume of l,2,2 trifluorotrichloroethane 20 to 30C The process of the present invention is first of all suitable for dyeings on polyester fibers or mixtures of such fibers with other fibers in all stages of processing, for example flocks, slubbings, cables, filaments, yarns, fabrics, knitted fabrics, non-Wovens or finished articles. This process is particularly suitable for the aftertreatment of, for example, finished articles in dry cleaning plants where a heating of the solvent bath is possible.

The following Example serves to illustrate the invention:

EXAMPLE A cross-wound bobbin made of polyester staple fiber yarn was treated for 90 minutes at 97C to 98C at a goods-to-liquor ratio of 1 20 in a dyebath containing calculated on the weight of the dry goods l of the disperse dyestuff of the formula and 4 g/l of a commercial carrier on the basis of methylnaphthalene, the pH of the dyebath being adjusted to 5.5 by means of acetic acid.

After the dyeing the goods were rinsed, subjected to a reductive cleaning in the usual manner and dried at 70 to 80C.

Portions of this dyeing were subsequently aftertreated for minutes each in the following listed organic solvents at the indicated temperatures and then dried.

Perchloroethylene 60C Trichloroethylene 35C Methanol 55C Mixture of 40% by volume of methylene chloride 60% by volume of 1,2,2-trifluoro-trichloroethane 30C These aftertreated dyeings and a sample of the dyeing which had not been aftertreated were subsequently exposed to light in the Xenotest-apparatus until the dyeing which had not been after-treated showed a very strong yellowing at the spot exposed to light. Compared with the non-aftertreated dyeing, this yellowing could not be observed with the aftertreated samples.

in addition thereto, other samples of the dyed goods were aftertreated for 10 minutes at C, 60C and 90C in perchloroethylene.

After an exposure to light for an equal length of time in the Xenotest-apparatus, the samples aftertreated at 20C showed only a slightly weaker yellowing than the dyeing which had not been subjected to an aftertreatment. The samples aftertreated at 60C and 90C showed, as already demonstrated at the treatment at 60C, no deterioration of the fastness to light. Within the scope of these aftertreating operations it could be observed however, that with the treatment carried out at 90C the solvent dyebath was strongly stained and the dyeing distinctly bleached. The tests carried out at other temperatures in perchloroethylene and those carried out in other solvents at the temperatures as indicated did in no case lead to a distinct staining of the aftertreating baths or to visible brightenings of the dyeings.

Similar results were obtained in all cases in which instead of the afore-mentioned dyestuff 0.1 of the disperse dyestuff of the formula was used for preparing the dyeings and, furthermore, a carrier on the basis of o-phenylphenol was used instead of one of the basis of methyl naphthalene.

We claim:

1. In a process for the production of dyeings and prints on linear polyester fibers with disperse dyestuffs applied with the assistance of carriers (dyeing promoters) from an aqueous medium, which dyeings and prints are fast to light and cannot be influenced by the dyeing promoting agents, the improvement of which comprises: aftertreating the carriercontaining dyeings and prints with an organic solvent selected from the group consisting of hydrocarbons, alcohols, esters and ethers, or a mixture of such solvents at a temperature between 20 and C.

2. A process as claimed in claim 1, wherein as organic solvents halogenated hydrocarbons are used.

3. A process as claimed in claim 2, wherein as solvents perchloroethylene or trichloroethylene are used.

4. A process as claimed in claim 1, wherein as organic solvents aliphatic alcohols having one to three carbon atoms are used.

5. A process as claimed in claims 4, wherein as solvent methanol is used. 

1. IN A PROCESS FOR THE PRODUCTION OF DYEINGS AN PRINTS ON LINEAR POLYESTER FIBERS WITH DISPERSE DYESTUFFS APPLIED WITH THE ASSISTANCE OF CARRIERS (DYEING PROMOTERS) FROM AN AQUEOUS MEDIUM, WHICH DYEINGS AND PRINTS ARE FAST TO LIGHT AND CANNOT BE INFLUENCED BY THE DYEING PROMOTING AGENTS, THE IMPROVEMENT OF WHICH COMPRISES: AFTER TREATING THE CARRIER CONTAINING DYEINGS AND PRINTS WITH AN ORGANIC SOLVENT SELECTED FROM THE GROUP CONSISTING OF HYDROCARBONS, ALCOHOLS, ESTERS AND ETHERS, OR A MIXTURE OF SUCH SOLVENTS AT A TEMPERATURES BETWEEN 20* AND 80*C.
 2. A process as claimed in claim 1, wherein as organic solvents halogenated hydrocarbons are used.
 3. A process as claimed in claim 2, wherein as solvents perchloroethylene or trichloroethylene are used.
 4. A process as claimed in claim 1, wherein as organic solvents aliphatic alcohols having one to three carbon atoms are used.
 5. A process as claimed in claims 4, wherein as solvent methanol is used. 